1. Field of the Invention
The invention relates to graphics for display. More particularly, the invention relates to methods and apparatus for scaling graphics display information.
2. Description of the Related Art
The aspect ratio of graphics displayed on a device, such as a television, is a numerical expression of the width to height of the graphics display. For standard television display format, e.g., National Television System Committee (NTSC) and Phase Alternation Line (PAL), the aspect ratio is 4:3, i.e., a “4” unit width corresponding to a “3” unit height, proportionally, regardless of the actual size of the screen. For wide screen digital television (DTV) formats for high definition television (HDTV) and some enhanced definition television (EDTV) formats, the aspect ratio is wider: 16:9, i.e., a “16” unit width corresponding to a “9” unit height, proportionally, regardless of the actual size of the screen.
Since there exists both graphics content meant for display on devices with a 4:3 aspect ratio and graphics content meant for display on devices with a 16:9 aspect ratio, content providers and service providers often are faced with the task of providing graphics in both aspect ratio formats or converting graphics between different aspect ratios. Conventional methods for converting graphics typically require that a portion of the converted graphics information for display be removed or cut off. Some conventional conversion methods use linear conversion techniques to fill out the final display window or screen, however such methods introduce distortion to the graphics. Moreover, distortion often is more pronounced with distortion-sensitive graphics information, such as logos, than it is with graphics information that is not as distortion-sensitive, such as text. Yet, conventional conversion techniques typically apply the same type or amount of aspect ratio conversion to all parts of the same graphics display information.